Do you cringe every time you think of your horse standing in mud? Do you wonder why your horse’s hooves are flaky and shelly even though you feed him the best biotin supplement? Do you feel concerned when your horse’s feet stink? If so, read on.
The saying, “no hoof no horse,” is a good one. Even better is: “no nutrition, no hoof, and hence, no horse.” At the root of many equine health issues are nutritional deficiencies and imbalances, and often the only way to truly heal your horse is by addressing the root problem. Here are some of the root causes of the most common infections threatening our horses’ hooves: thrush and White Line Disease (WLD).
What Are White Line Disease and Thrush?
Thrush is a bacterial and fungal disease of the outer and sometimes inner areas of a horse’s frog. Bacteria associated with thrush is anaerobic (cannot survive exposure to oxygen), and can eat away at your horse’s
frogs, the collateral grooves, and the central sulcus, and in very bad cases can spread to the entire hoof. There is often a smelly, black discharge associated with thrush and, in extreme cases, where thrush has entered the
inner hoof tissues, visible blood.
White Line Disease is a mostly fugal infection of the inner hoof wall, although some bacteria can be involved, too. It doesn’t involve the white line at all. When a horse has WLD, fungus enters the hoof through the whitish area of the hoof where the hoof wall meets the sole. Fungus generally enters when the hoof is structurally compromised, and works its way up the hoof, sometimes causing separations inside the hoof wall. WLD is most commonly diagnosed by visible separations between the hoof wall and the sole at the toe and hoof quarters. These separations often have a powdery white substance in them.
What Causes WLD and Thrush?
Thrush is caused by an unhealthy frog. Frogs are healthy when they receive circulation by contacting the ground with each step and when they are on a level plane with the heels of the hoof capsule, so as to avoid inappropriate loading of the hoof. Anything that creates an uneven frog, whether it be conformation issues (e.g. club feet) or trimming issues, as well as anything that prevents the frog from getting proper circulation by contacting the ground, is generally the root cause of thrush. Healthy frogs, even if exposed to lots of moisture, are not prone to thrush.
The root cause of WLD, on the other hand, is generally very difficult to pinpoint. That said, horses with poor hoof confirmation or quality, club feet, flared hooves, old abscess tracks, or quarter cracks are very susceptible to WLD since their hooves structurally allow an opening for fungus to enter. Additionally, laminitic horses are at risk, given that their laminae, which hold the layers of the hoof wall together, are already very compromised, making separation of the inner and outer hoof wall much easier. Moreover, fungus can thrive on the heat created by inflammation, and the blood plasma and dead tissue in the laminitic hoof.